There is a case where an electronic document which is created using a document creating application is printed on a paper, and content of the document printed on the paper is reviewed (check or correct of the described content). At this time, there is a case where handwritten comments and so on are described on the paper document. The handwritten comments may be recorded as minutes by being digitized after the review.
In order to digitize comments which are handwritten on the paper document, it is necessary to make two images correspond to each other to compare an image of the paper document on which the original electronic document is printed (printed image) to an image of the paper document on which comments are added. To do so, a code including an ID which uniquely represents the electronic document is printed when the original electronic document is printed as a paper document. Then, after adding handwritten comments on the printed paper document, the printed original electronic document and a scanned document are related, by extracting the ID by reading the code when scanning the paper document.
In addition, there is a method in which post-processing with respect to handwritten characters which are obtained after scanning is automatically performed, by being included information about the post-processing, for example, extracting or printing a difference image such as the handwritten comments, by comparing the print image to the read image which is obtained by scanning the paper document.
In this manner, in the related art, it was possible to make the original electronic document (printed image) correspond to the image on the paper document, on the basis of the code which is printed on the paper document.